Ignition coils



April '8, 1969 r .L. TOLLEY I 7,

' I IGNITION corps I Filed July 12, l967 v I Z2 I I s- E L\ i I l5 I HUnited States Patent 3,437,966 I IGNITION COILS Leslie Tolley, GreatBarr, Birmingham, England, assignor to Joseph Lucas (Industries)Limited, Birmingham, England Filed July 12, 1967, Ser. No. 652,894Claims priority, application Great Britain, Aug. 8, 1966, 35,380/ 66Int. Cl. H01f 27/04 US. Cl. 336-90 3 Claims ABSTRACT OF THE DISCLOSUREThis invention relates to ignition cOils of the kind including a hollowcasing, closed by an insulating cap, a core extending axially within thecasing and comprising a plurality of axially extending laminae and ahigh tension terminal carried by the insulating cap.

According to the invention in a coil of the kind specified one of saidlaminae extends from the core and is shaped to define a compressionspring, the Spring engaging a part associated with said terminal andserving electrically to interconnect said core and said terminal.

The accompanying cross-sectional view of an ignition coil illustratesone example of the invention.

Referring to the drawing the coil includes a hollow casing 11 closed bya truncated conical cap 12 of insulating material. Supported within thecasing 11 and extending axially between the cap 12 and an insulatingsupport 13 is a core 14 consisting of a plurality of laminae 1'5.Surrounding the core is a former 16 on which are wound the primary andsecondary windings 17 of the coil.

One of the laminae extends from the core 14 and is bent into contactwith the upper end of the core, the remainder of the extending portionof laminae being deformed to constitute an axially extending compressionspring 18.

The cap 12 is formed with a stepped axial bore 19 the narrower part ofwhich is closed by a conductive screw 21 the head 22 of which extendsinto the wider part of the bore 19 and constitutes the high tensionterminal of the ignition coil. The shank of the screw 21 extends throughthe cap 12 and into contact with the spring 18 thereby electricallyinterconnecting the high tension terice minal and the core 14 and urgingthe core 14 through the intermediary of the spring 18, into engagementwith the support 13. The cap 12 also serves to support the other twoterminals of the coil, one of which is connected within the coil to oneend of both the primary and secondary windings of the coil and is in useelectrically connected through a contact breaker to earth, and the otherof which is connected within the coil to the other end of the primarywinding of the coil and is in use connected to a DC. source, the otherend of the secondary winding of the coil being connected to the hightension terminal of the coil through the core and the spring 18.

Where the coil is oil filled, a rubber sealing ring 23 is trappedbetween the head 22 of the screw 21 and the stepped portion of the bore119 to prevent leakage of oil through the bore 19.

Having thus described my invention What I claim as new and desire tosecure by Letters Patent is:

1. An ignition coil comprising in combination a hollow casing, aninsulating cap closing said casing, a core extending axially within saidcasing and comprising a plurality of axially extending laminae, a coilsurrounding said core, a high tension terminal carried by saidinsulating cap, one of the laminae having an integral extension at itsend adjacent said insulating cap, said integral extension being bent todefine a pair of flat parallel portions integrally connected so as todefine a compression spring, one of said flat portions extending alongthe top edges of said laminae, and the other of said fiat portionsengaging a part associated with said terminal and serving electricallyto interconnect Said core and said terminal.

2. An ignition coil as claimed in claim 1 wherein said high tensionterminal is constituted by the head of a conductive screw and said partassociated with the terminal is constituted by the shank of the screw.

3. An ignition coil as claimed in claim 2 wherein the screw extendsthrough a bore in said insulating cap, there being a resilient sealingmember trapped between the head of the screw and the periphery of saidbore to prevent leakage of oil from the casing through said bore wherethe ignition coil is filled with oil.

References Cited UNITED STATES PATENTS LEWIS H. MYERS,

THOMAS J. KOZMA, Assistant Examiner.

Primary Examiner.

US. Cl. X.R. 336-92, 192

